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Biomedical subjects

J Goldstein

Publications and source records attributed to J Goldstein.

At least 109 records · Page 6Linked to original sources
PubMed1995

Identification of tyrosine 108 in coffee bean alpha-galactosidase as an essential residue for the enzyme activity.

The cDNA for coffee bean alpha-galactosidase (alpha-Gal) has been cloned and expressed in a baculovirus expression system. An early study of coconut alpha-Gal by chemical modification suggested that one tyrosine residue is at or near the active site. In order to identify such a critical residue, we replaced two tyrosine residues (positions 108 and 158) with phenylalanine by site-directed mutagenesis. The mutated DNA strands, as well as the wild-type ones, were subcloned into pVL vector and transformed into Sf9 insect cells for intracellular expression. The replacement of Tyr-158 with phenylalanine resulted in a mutant alpha-Gal (Y158F) which retained approx. 88% of the activity of wild-type enzyme. However, the substitution of Tyr-108 by phenylalanine (Y108F) almost abolished the enzymatic activity (1.8% of wild-type activity). The Vmax/Km value for the mutant Y108F was 0.027, which was over a 1000-fold lower than that of wild-type alpha-Gal. Our data suggest that Tyr-108 is critical for the enzymatic activity of alpha-Gal.

Baculoviridae↗
PubMed1995

NADPH-diaphorase distribution in the choroid after continuous illumination.

The role of nitric oxide (NO) in the regulation of the tone of the blood choroid vessels was investigated using the histochemical NADPH-diaphorase technique. Rats were continuously illuminated with white light, 12,000 lux, for 8 days and perfused after 1, 3, 10 and 20 days of total darkness. Cryostat sections were processed using the NADPH diaphorase histochemical method. An increase in reactive fibres was observed during days 1, 3 and 10, but after 20 days in darkness, reactivity was similar to that observed in control sections. These results indicate that NO plays a role in regulating the blood flow in the uveal vessels, and that there are changes in NO level dependent on the functional state of the retina.

Animals↗
PubMed1995

Red cell surface cysteine residue (285) of D polypeptide is not essential for D antigenicity.

BACKGROUND: Only one surface cysteine residue (285) has been thought to be involved in D antigenicity, according to studies using lyophilized or nonlyophilized red cell membranes. However, it has been reported that a 17-kDa chymotryptic fragment containing the N-terminus but not this cysteine residue is associated with D antigenicity. STUDY DESIGN AND METHODS: The role of the sulfhydryl (SH) group in D, c, and E antigenicity is assessed by using intact red cells treated with the reagents N-ethylmaleimide, 5,5'-dithiobis(2-nitrobenzoic acid), and 2-(4'-maleimidylanilino)- naphthalene-6-sulfonic acid. Antigenicity was appraised by hemagglutination titers and immunoprecipitation using human anti-D, -c, and -E. RESULTS: Treatment with N-ethylmaleimide or 5,5'-dithiobis(2-nitrobenzoic acid) at various concentrations (< or = 5 mM) or for various times (< or = 120 min) did not cause significant decrease in hemagglutination titers as compared to untreated intact red cells. Moreover, immunoprecipitation of Rh antigen-carrying peptides by human anti-D was not affected by prior treatment with N-ethylmaleimide or 2-(4'maleimidylanilino)-naphthalene-6-sulfonic acid. Efficacy of blockage of SH groups was demonstrated by inhibition of palmitic acid uptake by the Rh polypeptides for prior treatment with N-ethylmaleimide and by the presence of fluorescent Rh polypeptides for prior treatment with 2-(4'maleimidylanilino)-naphthalene-6-sulfonic acid. CONCLUSION: SH group involvement is not essential for D, c, or E antigenic expression in intact red cells.

Antibodies, Monoclonal↗
PubMed1995

Transnasal butorphanol in the treatment of acute migraine.

We studied transnasal butorphanol (Stadol NS) for pain relief during acute migraine in a multicenter, randomized, double-blind, placebo controlled trial using ambulatory patients at 10 geographically diverse headache centers. Patients were volunteer adults diagnosed with migraine with or without aura by International Headache Society criteria. One hundred fifty-seven patients completed the study. We treated the pain of one headache in each patient with either transnasal butorphanol (n = 107) or transnasal placebo (n = 50). Pain relief, pain intensity, nausea, vomiting, and effect on function were measured periodically. Adverse experiences were documented. Global assessments were made at follow-up. With butorphanol, migraine pain was reduced from moderate, severe, or incapacitating to slight or absent for 35 patients (33%) within 30 minutes, for 50 patients (47%) within 1 hour, and for 76 (71%) within 6 hours, compared to 2 (4%), 8 (16%) and 15 (30%) respectively for placebo. Side effects were prominent, though confounded by the migraine. The most common side effects, compared to placebo, were dizziness (58% vs 4%), nausea and/or vomiting (38% vs 18%), and drowsiness (29% vs 0%). We conclude that transnasal butorphanol is a useful analgesic for the pain of acute migraine. Its prominent side effects and low self reinforcement rate may limit its usefulness in some patients, while increasing its appropriateness for others.

Acute Disease↗
PubMed1995

Use of hyperbaric oxygen in rheumatic diseases: case report and critical analysis.

Hyperbaric oxygen has been used in patients with rheumatic disease for many years without reports of untoward or unusual complications for a variety of non-rheumatic indications. Recent evidence that hyperbaric oxygen inhibits the actions of certain cytokines, acts as an immune modulator and may help cognitive dysfunction has resulted in a re-examination of its potential role in rheumatic diseases. A case report of a lupus/scleroderma crossover patient is presented whose cognitive dysfunction improved after hyperbaric oxygen therapy. The history of hyperbaric oxygen and its physiology are related, along with a focused review of its effects on the immune and central nervous systems. Areas which might warrant further consideration by rheumatologists are outlined, as well as areas of concern.

Cognition Disorders↗
PubMed1995

Copolymer 1 reduces relapse rate and improves disability in relapsing-remitting multiple sclerosis: results of a phase III multicenter, double-blind placebo-controlled trial. The Copolymer 1 Multiple Sclerosis Study Group.

We studied copolymer 1 (Copaxone) in a multicenter (11-university) phase III trial of patients with relapsing-remitting multiple sclerosis (MS). Two hundred fifty-one patients were randomized to receive copolymer 1 (n = 125) or placebo (n = 126) at a dosage of 20 mg by daily subcutaneous injection for 2 years. The primary end point was a difference in the MS relapse rate. The final 2-year relapse rate was 1.19 +/- 0.13 for patients receiving copolymer 1 and 1.68 +/- 0.13 for those receiving placebo, a 29% reduction in favor of copolymer 1 (p = 0.007) (annualized rates = 0.59 for copolymer 1 and 0.84 for placebo). Trends in the proportion of relapse-free patients and median time to first relapse favored copolymer 1. Disability was measured by the Expanded Disability Status Scale (EDSS), using a two-neurologist (examining and treating) protocol. When the proportion of patients who improved, were unchanged, or worsened by > or = 1 EDSS step from baseline to conclusion (2 years) was evaluated, significantly more patients receiving copolymer 1 were found to have improved and more receiving placebo worsened (p = 0.037). Patient withdrawals were 19 (15.2%) from the copolymer 1 group and 17 (13.5%) from the placebo group at approximately the same intervals. The treatment was well tolerated. The most common adverse experience was an injection-site reaction. Rarely, a transient self-limited systemic reaction followed the injection in 15.2% of those receiving copolymer 1 and 3.2% of those receiving placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Laryngeal function in postpolio patients.

Of the 250,000 survivors of the polio epidemics, approximately 25% experience progressive muscle weakness known as postpolio syndrome (PPS). Laryngeal function in postpolio patients previously has not been studied. This paper presents data detailing laryngeal function in a group of postpolio patients who had been evaluated for swallowing complaints. Nine patients underwent comprehensive history and physical exam, acoustical voice analysis, and laryngeal videostroboscopic endoscopy. Three patients underwent laryngeal electromyography (EMG) evaluation. Results indicated some degree of phonatory or laryngeal deficit in all subjects. Subjects with dysphagia also demonstrated vocal fold paralysis. EMG revealed decreased recruitment and increased amplitude, findings consistent with EMG studies in skeletal muscle in postpolio patients. Results suggest that postpolio patients who complain of swallowing difficulties are at risk for laryngeal pathology.

Aged↗
PubMed1994

Rh(D) antigen expression and isolation of a new Rh(D) cDNA isoform in human erythroleukemic K562 cells.

Human erythroleukemic K562 cells are known to have several erythroid properties. K562 cells possess Rh mRNAs, but expression of Rh proteins has not previously been reported. We immunoprecipitated Rh protein from K562 cell lysate using rabbit anti-Rh and detected Rh(D) antigens on K562 cells using fluorescence-activated cell sorting (FACS). These results suggest that K562 cells will be useful as an expression model for most Rh antigens. We also cloned a new Rh(D) cDNA isoform (RhK562-II), from a K562 cDNA library using polymerase chain reaction (PCR) with 5' and 3' end oligonucleotides of the published Rh(e/E) antigen encoding cDNA sequence as primers. Sequence analysis showed that RhK562-II is composed of 951 nucleotides (316 amino acids), identical to the first 939 nucleotides (exons 1 to 6) of one of the Rh(D) cDNAs (RhXIII), except for nucleotide 654 (C-->G exchange). However, this exchange is the same as that of another published Rh(D) cDNA (RhPII cDNA). RhK562-II is deprived of exons 7 and 8 (nucleotides 940 to 1,153), followed by an identical sequence up to the 3' end of the open-reading frame of the RhXIII cDNA, which causes a frame-shift mutation and produces a premature stop codon. In vitro expression of RhK562-II using the transcription and translation rabbit reticulocyte lysate system produced two major Rh-related proteins (30 kD and 25 kD), which were immunoprecipitated by rabbit polyclonal anti-Rh and separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).

Amino Acid Sequence↗
PubMed1994

Characterization of illudin S sensitivity in DNA repair-deficient Chinese hamster cells. Unusually high sensitivity of ERCC2 and ERCC3 DNA helicase-deficient mutants in comparison to other chemotherapeutic agents.

Illudins, novel natural products with a structure unrelated to any other known chemical, display potent in vitro and in vivo anti-cancer activity against even multi-drug resistant tumors, and are metabolically activated to an unstable intermediate that binds to DNA. The DNA damage produced by illudins, however, appears to differ from that of other known DNA damaging toxins. The sensitivity pattern of the various UV-sensitive cell lines differs from previously studied DNA cross-linking agents. Normally, the ERCC1- (excision repair cross complementing) and ERCC4-deficient cell lines are most sensitive to DNA cross-linking agents, with ERCC2-, ERCC3- and ERCC5-deficient cell lines having minimal sensitivity. With illudins the pattern is reversed, with ERCC2 and ERCC3 being the most sensitive. The sensitivity to illudins in complementation groups 1 through 3 is due to a deficiency of the ERCC1-3 gene products, as cellular drug accumulation studies revealed no differences in transport capacity or total drug accumulation. Also, a transgenic cell line in which ERCC2 activity was expressed through an expression vector regained its relative resistance to the illudins. The EM9 cell line, which displays sensitivity to monoadduct producing chemicals, was not sensitive. Thus, excision repair is involved in repair of illudin-induced damage and, unlike other anti-cancer agents, the involvement of ERCC2 and ERCC3 helicases is critical for repair to occur. The requirement for ERCC2 and ERCC3, combined with the finding that ERCC1 but not ERCC2 is upregulated in drug-resistant tumors, may explain the efficacy of illudins against drug-resistant tumors. The inhibition of DNA synthesis in cells within minutes after exposure to illudins at nanomolar concentrations may be related to the finding that the ERCC3 gene product is actually the p89 helicase component of the BTF2 (TFII) basic transcription factor and the high sensitivity of ERCC3-deficient cells to illudins.

Animals↗
PubMed1994

Cloning and functional expression of a cDNA encoding coffee bean alpha-galactosidase.

Purified coffee bean alpha-galactosidase (alpha Gal) has been used for removing terminal alpha-galactose residues from the glyco-conjugates at the red cell surface, in studies of blood group conversion. Here, we report the isolation and sequence of the full-length clone for coffee bean alpha Gal by using the polymerase chain reaction (PCR) and rapid amplification of cDNA ends (RACE) techniques. The cDNA clone (1.4 kb) contains a single open reading frame which encodes a protein of 378 amino acids (aa). Its authenticity is confirmed by perfect alignment of aa sequences obtained from purified coffee bean alpha Gal, and by immune reaction with the antibody raised against the enzyme. Furthermore, the protein produced in insect cells shows enzymatic activity towards a synthetic alpha Gal substrate, p-nitro-phenyl-alpha-galactopyranoside.

Amino Acid Sequence↗
PubMed1994

Design and evaluation of a thrombin-activable plasminogen activator.

A new chimeric plasminogen activator with high fibrin affinity was designed to bind fibrin and to initiate clot destruction, following activation by thrombin. The chimeric activator, 59D8-scuPA-T, was made from the Fab fragment of an anti-fibrin antibody (59D8) and a C-terminal portion of a thrombin-activable low molecular weight single-chain urokinase plasminogen activator, scuPA-T, obtained by deletion of Phe-157 and Lys-158 from low molecular weight single-chain urokinase-type plasminogen activator (scuPA) by site-directed mutagenesis. The chimeric molecule had a molecular mass of 91,000, a value consistent with one 59D8 light chain (M(r) = 27,000) and one 59D8 heavy-chain Fd fragment fused to low molecular weight scuPA (M(r) = 64,000). According to its design, 59D8-scuPA-T was activated by thrombin but not by plasmin, whereas the control chimeric molecule, 59D8-scuPA, was activated by plasmin but not by thrombin. When activated by thrombin, 59D8-scuPA-T converted plasminogen to plasmin. In vitro plasma clot lysis assays showed that 59D8-scuPA-T lysed clots performed by thrombin and that heparin and hirudin could prevent clot lysis. When incorporated as part of a thrombin-induced clot, only 59D8-scuPA-T was able to lyse the clot while 59D8-scuPA and high molecular weight scuPA were ineffective. Together these results demonstrate that 59D8-scuPA-T is a thrombin-activable plasminogen activator that offers selective thrombolysis of thrombin-rich clots over more established, aged clots, and may also act as an antithrombotic agent.

Base Sequence↗
PubMed1994

Transfusions to group O subjects of 2 units of red cells enzymatically converted from group B to group O.

BACKGROUND: It has previously been shown that full-unit (200 mL) transfusions of red cells (RBCs) enzymatically converted from group B to group O by treatment with alpha-galactosidase (ECO RBCs) are both safe and efficacious for normal group O or A subjects. STUDY DESIGN AND METHODS: The present study describes the results of a comprehensive clinical and serologic assessment of 2-unit (400 mL) ECO RBC transfusions to each of four normal group O subjects (after each had donated 1 unit of whole blood). RESULTS: Clinical (hematologic tests, chemistry analysis, urinalysis) and serologic analyses revealed no evidence of immediate or delayed transfusion reaction, despite a threefold to fivefold elevation in pre-existing anti-B antiglobulin titer. 51Cr-labeled ECO RBCs were administered to one of the four subjects to allow direct measurement of ECO RBC survival in the circulation, which indicated that it was normal (24-hour survival, 95%; t1/2, 29.5 days). The observed increases in hemoglobin (by 1.3 +/- 0.4 g/dL [13 +/- 4 g/L]) and hematocrit (by 3.2 +/- 0.8% [0.032 +/- 0.008]) in transfused subjects provide further evidence of the efficacy of these cells in vivo. CONCLUSION: These results extend those observed in our earlier 1-unit transfusion studies and suggest that ECO RBCs pose little risk and will be useful in transfusion medicine.

ABO Blood-Group System↗
PubMed1994

Familial occurrence of multiple cutaneous chondromas.

True cutaneous chondromas are rare lesions with an uncertain pathogenesis. We report an unusual case of a patient with multiple cutaneous chondromas of the face. One of the patient's siblings, a brother, and that brother's son had similar facial lesions. We conclude that this familial pattern suggests an autosomal dominant mode of transmission.

Adult↗
PubMed1994

Interstitial cell (Leydig) tumor in an eland (Taurotragus oryx).

We observed an interstitial cell tumor in an 18-mo-old captive eland bull (Taurotragus oryx) in Tel Aviv, Israel. The histological description of the tumor in the eland was similar to that described in cattle; however, the appearance of a moderate amount of lipid vacuoles in the cytoplasm of the neoplastic cells was uncharacteristic for bovine interstitial cell tumors. The eland also had clinical signs of gynecomastia.

Animals↗